Control systems for the automatic operation of storage and retrieval machines have, in recent years, become more comprehensive and sophisticated. This has increased the speed, accuracy and durability of storage and retrieval machines and opened the way for further developments which were not previously possible or even considered.
In present control systems for storage and retrieval machines, a remote control source gives an on-board control means a command to move to a particular storage location and either deliver or retrieve an object at the storage location. Either the remote control source or the on-board control means provides specific instructions for movement of the base, the carriage and the shuttle of the storage and retrieval means. The movemment instructions are utilized by further control and/or drive means to operate the base, carriage and shuttle to the necessary locations. The movement instructions include, e.g., distance to move or location to move to, maximum velocity, acceleration rate and deceleration rate, for both the base and the carriage. One or more of the instructions are aslo provided for the shuttle. Control systems at the level of sophistication provide a high degree of control over the entire operation of the storage and retrieval machine.
It has been recognized that factors such as the size and type of the load objects carried by the storage and retrieval machine affect the maximum velocity, the acceleration, and the deceleration at which the base and carriage can move. Present controls for storage and retrieval machines take such factors into account in providing movement instructions. The invention disclosed herein is an improvement to storage and retrieval machine controls and requires further that the direction of movement of the base and carriage be considered in providing either acceleration or deceleration instructions to the base and carriage.